Chinese pharmaceutical group CanSino Biologics said demand for its Covid-19 vaccine was “dying down” in China after the abrupt end of the country’s tough zero-Covid policies, underscoring the challenges facing the sector in the largest remaining under-vaccinated market.

CanSino was in the middle of rolling out an inhaled version of a coronavirus vaccine when China shed lockdown restrictions in early December. The vaccine had received emergency approval, adding to the existing dozen domestic vaccines serving the Chinese population.

Yu Xuefeng, co-founder and chief executive of the Tianjin-based group, said it had rolled out “millions of doses” before the “surprise end of zero-Covid”. But Yu added that the campaign was outpaced by the virus, which infected an estimated 80 per cent of the population within weeks.